21221112001 has 2 divisors, whose sum is σ = 21221112002. Its totient is φ = 21221112000.

The previous prime is 21221111959. The next prime is 21221112023. The reversal of 21221112001 is 10021112212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18496272001 + 2724840000 = 136001^2 + 52200^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221112001 - 2⁹ = 21221111489 is a prime.

It is not a weakly prime, because it can be changed into another prime (21221112061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610556000 + 10610556001.

It is an arithmetic number, because the mean of its divisors is an integer number (10610556001).

Almost surely, 2^21221112001 is an apocalyptic number.

It is an amenable number.

21221112001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221112001 is an equidigital number, since it uses as much as digits as its factorization.

21221112001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21221112001 its reverse (10021112212), we get a palindrome (31242224213).

The spelling of 21221112001 in words is "twenty-one billion, two hundred twenty-one million, one hundred twelve thousand, one".